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My Zoom - Crash Evaluation Please

jpzend125

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Hello everyone. I have flown my M2Z (with a smart controller) for a few months, even in Aruba the second week of this month. Never went near the water...but on Sunday, I was flying over the Hudson River, from a park on the water. I flew about 14 minutes, taking video the entire time. the day was partly cloudy, 5mph wind, no precip and had the bird VSOL the entire flight. Upon returning to land, i flew along a path we were walking on and then out over the water (about 10 feet from shore), at about 10-12 feet up. I was flying on "P" mode. Suddenly the bird started down, paused a couple of feet from the water, but kept going until it went into the river. When it first started down, i pushed the left controller up and yet, it still descended. As it got closer to the water, i got a controller signal error and before i knew it, my beloved drone joined Davy Jones. I was LESS THAN 100 YARDS from it! I read a bunch of threads and was able to download the .log flight log, but can't read it on AirData. I can't attach it here, since it's not a supported file type. I had to read the SC card on my PC to even find it. Can someone help me figure out what went wrong? One other thing that is weird is that i get 2 different video files every time i fly, so i wonder is it possible that the SC has 2 profiles for each flight? The video stops well before I came back over the path. I have 2 video files, each 5 minutes, but the flight was 14 minutes. Help me Obi Wan.
 
Hello everyone. I have flown my M2Z (with a smart controller) for a few months, even in Aruba the second week of this month. Never went near the water...but on Sunday, I was flying over the Hudson River, from a park on the water. I flew about 14 minutes, taking video the entire time. the day was partly cloudy, 5mph wind, no precip and had the bird VSOL the entire flight. Upon returning to land, i flew along a path we were walking on and then out over the water (about 10 feet from shore), at about 10-12 feet up. I was flying on "P" mode. Suddenly the bird started down, paused a couple of feet from the water, but kept going until it went into the river. When it first started down, i pushed the left controller up and yet, it still descended. As it got closer to the water, i got a controller signal error and before i knew it, my beloved drone joined Davy Jones. I was LESS THAN 100 YARDS from it! I read a bunch of threads and was able to download the .log flight log, but can't read it on AirData. I can't attach it here, since it's not a supported file type. I had to read the SC card on my PC to even find it. Can someone help me figure out what went wrong? One other thing that is weird is that i get 2 different video files every time i fly, so i wonder is it possible that the SC has 2 profiles for each flight? The video stops well before I came back over the path. I have 2 video files, each 5 minutes, but the flight was 14 minutes. Help me Obi Wan.

Yes - start a thread for this incident in "Mavic Crash & Flyaway Assistance". First you need to post the original txt flight log, which is a supported file type. It's not any of the .log files. Instructions below:

Flight log retrieval and analysis guide
 
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Moved to it's own thread!!


Carry on :)
 
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You guys are exceptional! Wish everyone was as patient. Here are the .txt and the .dat files from the SC card.
 

Attachments

  • 20-01-26-01-47-20_FLY011.DAT
    8.1 MB · Views: 16
  • DJIFlightRecord_2020-01-26_[13-48-10].txt
    1.5 MB · Views: 16
The log indicates that repetitive throttle down control input were applied near the end of the flight to gradually lower the altitude before the throttle stick was held fully down to land the drone. Are you sure you have uploaded the correct log file ?

1580242189872.png
 
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I'm a bit puzzled ... to me it looks that you descended into the water all by yourself? You applied negative throttle numerous times & the AC reacted correctly everytime by decreasing the height, once low enough the AC when into forceland mode. You had a short connection issue but that was long before you steered it down.

Throttle down into water.jpg
 
Last edited:
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I'm a bit puzzled ... to me it looks that you descended into the water all by yourself? You applied negative throttle numerous times & the AC reacted correctly everytime by decreasing the height, once low enough the AC when into forceland mode. You had a short connection issue but that was long before you steered it down.

View attachment 92454
That's the correct record. While i was panicked, i remember throttling down, but then stopped and it continued down. By that time, as you said, it went into landing mode and dropped. However, i have flown enough not to throttle down, when i should be throttling up. I have taken off and landed on the small, raised deck behind my house and never lost control like this. When i land (intentionally), the drone pauses and then lands, but my throttle is full down the whole time. Pilot error is more than likely, but the AC didn't behave like this at any time in past...

The last series of red lines indicate (if i read them right) that i went up and down in a very erractic way and this isn't my regular behavior.
 
... The last series of red lines indicate (if i read them right) that i went up and down in a very erractic way and this isn't my regular behavior.
No that red graph that shows your throttle (left stick forward/backwards), shows that you numerous times move the stick from centered to full backwards (ie. you command max descent). Just before the Auto landing starts you held the stick to max descent approx 3sec.

This a zoomed in graph:
Full down.jpg
 
I can't argue with the record. I must have panicked. The up and down "numerous times" is not my style when near the deck. Again, I am new to reading these graphs, so am i wrong when i say that I don't see any increase in height despite the throttle being pushed forward?

I still feel something went wrong with the AC, but this evidence is pretty clear. Now, i have got to try to snag it somehow, so i can use my DJI refresh. thank you so much for your help. My apologies to Wyldwings for being rude and hijacking his thread. So glad he found it!
 
I can't argue with the record. I must have panicked. The up and down "numerous times" is not my style when near the deck. Again, I am new to reading these graphs, so am i wrong when i say that I don't see any increase in height despite the throttle being pushed forward?

I still feel something went wrong with the AC, but this evidence is pretty clear. Now, i have got to try to snag it somehow, so i can use my DJI refresh. thank you so much for your help. My apologies to Wyldwings for being rude and hijacking his thread. So glad he found it!
You didn't pushed the throttle stick forward from centered ... you moved it repeatedly between centered & full back (to full descent) ... look at the red graph, it goes between value 0 to -10 000. You never commanded the AC to ascend in the end of the flight ... in fact the last distinct ascend input you gave were at 380sec into the flight, then you had a vague one (only lasted for 3sec & to 1/10:th of full) at 739sec, probably a recoil over centered position from releasing the stick to fast.
 
Thank you slup!. How can i open the files and see the whole flight? What did you use to show me the records?

To start up I suggest you head over to sar104's well compiled guide & read it through, here it is --> Flight log retrieval and analysis guide

The 2 easiest ways to get an overview from your .TXT flight log is either --> PhantomHelp or --> Airdata , which both are free or have free alternatives.

Both gives you a graphical interface with maps from were you can simulate the flight & take note of telemetric data, messages given during flight & stick inputs. It's a slight edge towards Airdata as they provide a bit more data... & even more if you pay a subscription.

View from PhantomHelp:

Phantomhelp.jpg

Views from Airdata:

Airdata.jpg

You can also go the "engineering way" ... this with CsvView, which was what I showed you. You download it here --> CsvView & DatCon
In this way you access the raw flight log & you by yourself pick & chose what you want to study closer according to a theory you have about the event. CsvView reads both .TXT & .DAT files ... the .TXT & .DAT files usually differ a bit in content, in order to go to the depth you will need both files.

Just to set a side a full weekend & dig in :)
 
One of the first things I learned flying my drone was, if something unexpected happens, let go of the sticks and see if the drone stabilizes. If so, then take a deep breath and try carefully to retrieve the drone back to you.

It saved me several crashes, once (before I had my MA) I only realized how close I had been to a crash as I reviewed the video.
 
To start up I suggest you head over to sar104's well compiled guide & read it through, here it is --> Flight log retrieval and analysis guide

The 2 easiest ways to get an overview from your .TXT flight log is either --> PhantomHelp or --> Airdata , which both are free or have free alternatives.

Both gives you a graphical interface with maps from were you can simulate the flight & take note of telemetric data, messages given during flight & stick inputs. It's a slight edge towards Airdata as they provide a bit more data... & even more if you pay a subscription.

View from PhantomHelp:

View attachment 92487

Views from Airdata:

View attachment 92488

You can also go the "engineering way" ... this with CsvView, which was what I showed you. You download it here --> CsvView & DatCon
In this way you access the raw flight log & you by yourself pick & chose what you want to study closer according to a theory you have about the event. CsvView reads both .TXT & .DAT files ... the .TXT & .DAT files usually differ a bit in content, in order to go to the depth you will need both files.

Just to set a side a full weekend & dig in :)
Thanks again, you have been great and i very much appreciate your patience!
 
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One of the first things I learned flying my drone was, if something unexpected happens, let go of the sticks and see if the drone stabilizes. If so, then take a deep breath and try carefully to retrieve the drone back to you.

It saved me several crashes, once (before I had my MA) I only realized how close I had been to a crash as I reviewed the video.
The more I think about it, the more i am sure i panicked. This is great advice i will follow if/when i get a new drone.
 
Just a question...Is it at all possible that the controller could have been at fault in this case?
 
Just a question...Is it at all possible that the controller could have been at fault in this case?
The AC did exactly what the RC commanded it to do during the whole flight ... so no, that's not my belief.
 
Hello everyone. I have flown my M2Z (with a smart controller) for a few months, even in Aruba the second week of this month. Never went near the water...but on Sunday, I was flying over the Hudson River, from a park on the water. I flew about 14 minutes, taking video the entire time. the day was partly cloudy, 5mph wind, no precip and had the bird VSOL the entire flight. Upon returning to land, i flew along a path we were walking on and then out over the water (about 10 feet from shore), at about 10-12 feet up. I was flying on "P" mode. Suddenly the bird started down, paused a couple of feet from the water, but kept going until it went into the river. When it first started down, i pushed the left controller up and yet, it still descended. As it got closer to the water, i got a controller signal error and before i knew it, my beloved drone joined Davy Jones. I was LESS THAN 100 YARDS from it! I read a bunch of threads and was able to download the .log flight log, but can't read it on AirData. I can't attach it here, since it's not a supported file type. I had to read the SC card on my PC to even find it. Can someone help me figure out what went wrong? One other thing that is weird is that i get 2 different video files every time i fly, so i wonder is it possible that the SC has 2 profiles for each flight? The video stops well before I came back over the path. I have 2 video files, each 5 minutes, but the flight was 14 minutes. Help me Obi Wan.
strange the speech of the double video file.if you read the log put the PC screens only so you can know what really happened even if from what you wrote it would seem that the fail safe procedure has been activated, what settings you had regarding the 'rth? height?
 
I don't remember, but I usually have it at 100'. I am not sure what you mean about the double videos. If I could see the whole flight on video, it might help me find where it went it. The flight records show 14 mins, but I have 2 vids, each exactly 5 minutes and they don't overlap. In fact, i started recording from take off and never turned it off. The first one starts well after take off, lasts 5 mins, then there is a gap and the next one goes for 5 mins, but ends well before i crash. This happened the last time i flew. the first vid was 5 mins, the second one 2:30 mins, but the flight was less than 10 mins.
 
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